In the bowl of a food processor pulse the flour, sugar, salt, pistachios, and pulse for 1 minute until nuts are finely ground. Add the orange flower water and cardamom and pulse for another 30 seconds until completely mixed.

Add the cold butter pieces and pulse until the ingredients begin to stick together. The dough will still be crumbly.

Turn the dough onto a lightly floured counter or board. Quickly press the dough together with your hands and shape it into a long log about 1-1/2 inches in diameter. (Use wet hands if necessary to shape the dough.) Place the log on a piece of plastic wrap or parchment paper. Tightly roll the wrap around the log and twist the ends to seal them securely. Refrigerate for 1 – 2 hours or up to 5 days. It freezes well. I often double the recipe and keep a log in the freezer for unexpected occasions.

Preheat oven to 325º. Line a large baking sheet (half sheet tray) with parchment paper.

Slice the chilled dough into 1⁄2-inch-thick coins and place them about 1 inch apart on the prepared baking sheets. If desired, brush the top of each cookie with water and sprinkle with sugar. Bake for 15 minutes or until cookies are lightly golden brown on both top and bottom. Let the cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely. Store the cookies in an airtight container at room temperature for up to 2 weeks.